A graphics processing unit (GPU), occasionally called a visual processing unit (VPU), is a specialized electronic circuit designed to rapidly manipulate and alter memory to accelerate the creation of images in a frame buffer intended for output to a display device. GPUs are occasionally used in embedded systems, mobile phones, personal computers, workstations, and game consoles. Sometimes they are standalone integrated circuits, other time they are incorporated into larger devices, such as systems-on-a-chip (SoC). Modern GPUs are very efficient at manipulating computer graphics and image processing, and their highly parallel structure makes them more efficient than general-purpose CPUs for programs where the processing of large blocks of data is done in parallel.
In computers, hardware performance counters, or performance monitoring unit (PMUs) are generally a set of special-purpose registers built into modern microprocessors to store the counts of hardware-related activities within computer systems. Compared to software profilers, hardware counters provide low-overhead access to a wealth of detailed performance information related to CPU's functional units, caches, and main memory.
Design for testing or design for testability (DFT) consists of integrated circuit (IC) design techniques that add testability features to a hardware product design. The added features make it easier to develop and apply manufacturing tests to the designed hardware. Often the purpose of manufacturing tests is to validate that the product hardware contains no manufacturing defects that could adversely affect the product's correct functioning.
In addition to being useful for manufacturing “go/no go” testing, the feature can also be used to “debug” chip designs. In this context, the chip is exercised in normal or functional mode (for example, a computer or mobile-phone chip might execute assembly language instructions). At any time, the chip may be re-configured into “test mode”. At this point the full or partial internal state can be dumped out, or set to any desired values, by use of the DFT features. Another use of DFT to aid debug consists of scanning in an initial state to all memory elements and then go back to functional mode to perform system debug. The advantage is to bring the system to a known state without going through many clock cycles. This use of DFT features, along with the clock control circuits are a related sub-discipline of logic design called “Design for Debug” or “Design for Debuggability” (DFD).